It is increasingly common to wish to use glass-fiber distribution frame inserts with monitoring in glass-fiber distribution frames. The units referred to as coupler modules or monitoring modules are used in 19″ mounting racks and can be combined with standard plug modules.
In this regard, it is known for the glass-fiber coupler module to comprise a coupler by means of which the signals of at least one glass fiber are split between at least two outgoing glass fibers, one outgoing glass fiber being used for monitoring purposes. Further, the known glass-fiber coupler modules comprise a first and second group of couplings, the second group of couplings being arranged on the front panel. Plugs coming from the rear of the glass-fiber coupler module are accommodated by the first group of couplings and passed into the coupler via plugs inserted on the opposite side of the coupling. The glass fibers with a plug then run from the coupler to the couplings in the second group. It is often sufficient to monitor only the TX glass fibers. The rear RX glass-fiber plugs are thus inserted directly into the coupling on the front panel. The TX glass-fiber plugs are, on the other hand, inserted into the couplings in the first group and passed via the coupler to the second group of couplings. Owing to the fact that in this manner only half the glass fibers need to be passed to the coupler, the minimum bending radii do not present any problems. One disadvantage of the known glass-fiber coupler module is the maintenance problems associated with it. In the case of glass-fiber coupler modules, after a certain amount of time it is necessary to clean the plugs. Owing to the fact that there is only a small amount of space, it is extremely difficult to remove the plugs inserted in the first and second group of couplings within the housing without the use of a tool. Furthermore, it is nearly impossible to withdraw a plug without touching the adjacent glass fibers and thus influencing their transmission characteristics.